Abstract
A modified fiber-optic Sagnac interferometer with a stable π/2 phase bias is demonstrated for the demodulation of diaphragm-based acoustic sensors. The phase bias is obtained by introducing a nonreciprocal frequency shift between the counter-propagating waves. The system is passive and without complicated servo-control for phase stabilization. Interrogated by the proposed demodulation system, a 100 nm-thick graphite diaphragm-based acoustic sensor demonstrated a minimum detectable pressure level of ∼ 450 μPa/Hz1/2at the frequency of 5 kHz and the output signal stability is less than 0.35 dB over an 8-hour period.
| Original language | English |
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| Title of host publication | Fifth Asia-Pacific Optical Sensors Conference, APOS 2015 |
| Publisher | SPIE |
| Volume | 9655 |
| ISBN (Electronic) | 9781628418651 |
| DOIs | |
| Publication status | Published - 1 Jan 2015 |
| Event | 5th Asia-Pacific Optical Sensors Conference, APOS 2015 - Lotte City Hotel Jeju, Jeju, Korea, Republic of Duration: 20 May 2015 → 22 May 2015 |
Conference
| Conference | 5th Asia-Pacific Optical Sensors Conference, APOS 2015 |
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| Country/Territory | Korea, Republic of |
| City | Jeju |
| Period | 20/05/15 → 22/05/15 |
Keywords
- acoustic sensor
- graphite diaphragm
- Optical fiber sensor
- Sagnac interferometer
ASJC Scopus subject areas
- Applied Mathematics
- Computer Science Applications
- Electrical and Electronic Engineering
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics